Methods of producing and applying textile finishes and finishes produced by such methods

ABSTRACT

THE PROCESS OF PRODUCING CARBAMATE FINISHES BY REACTING AMONOCARBAMATE WITH FORMALDEHYDE IS CONTINUED BY REACTING FREE EXCESS FORMALDEHYDE LEFT AFTER THE REACTION WITH ETHYLENE UREA, PROPYLENE UREA OR GLYOXAL AND UREA TO SUBSTANTIALLY REDUCE THE FREE FORMALDEHYDE AND DIMINISH THE VOLATILITY OF THE FINISH.

United States Patent 3,590,100 METHODS OF PRODUCING AND APPLYING TEX- TILE FINISHES AND FINISHES PRODUCED BY SUCH METHODS Herman G. Weiland, Westfield, N.J., assignor to Arkansas Company, Inc., Newark, NJ. No Drawing. Filed Jan. 24, 1967, Ser.- No. 611,268 Int. Cl. C08g 37/32; D06m 13/34 US. Cl. 260-849 3 Claims ABSTRACT OF THE DISCLOSURE The process of producing carbamate finishes by reacting amonocarbamate with formaldehyde is continued by reacting free excess formaldehyde left after the reaction with ethylene urea, propylene urea or glyoxal and urea to substantially reduce the free formaldehyde and diminish the volatility of the finish.

This invention relates to the finishing of fabrics, particularly cotton fabrics and cotton polyester blends so as to make them wrinkle and crush resistant, resistant to scorching and yellowing and capable of being laundered with the use of hypochlorite bleaching and acid sours in the rinse without suffering any deleterious effects, including substantial loss in tensile strength. The invention is particularly concerned with such finishes and methods of producing them.

There are many finishes of this type which are known in prior art, some producing better results than others, some being effective in one way while being deleterious in other respects. A study and testing of various existing finishes has shown that among the most efi'ective ones are the carbamate finishes. They are produced by reacting a monocarbamate, such as methyl carbamate, ethyl carbamate, propyl carbamate, butyl carbamate, methoxyethyl carbamate or hydroxyethyl carbamate with two or more moles of formaldehyde, the reaction taking place in an alkaline aqueous solution at a pH range of 9.5 to 10.5. :For example, dimethylol methyl carbamate is produced in accordance with the following formula showing the approximate molar proportions:

(1 mole) (2.25 Moles) ii") (free) CHaO-CN(CHOH) HOHO (0.8 moles) It is apparent that the reaction producing the methylol derivative does not go to completion and that an excess of formaldehyde remains present in the reaction product.

Practical experience has shown that this excess of formaldehyde consititutes a serious drawback of carbamate finishes which have otherwise good qualities, since they impart dimensional control and excellent wash and wear characteristics and still retain a soft hand, the hand being essentially unchanged. Excess formaldehyde has become a problem in finishing plants Where textiles are being treated with these finishes. In addition, residual amounts of formaldehyde are left in the goods even after drying and curing and can be detected not only in the fabric but sometimes even in the garment made from the fabric.

Another drawback of carbamate finishes is that they are quite volatile and have a tendency to sublime on drying and even in storage. For this reason, they do not lend themselves well to permanent press or delayed curing processes. For example, a garment made from uncured fabric treated with a conventional carbamate finish may 3,590,100 Patented June 29, 1971 lose most of its finish by sublimation before the garment is given the final processing.

An object of the present invention is the provision of finishes which will have all the advantages of carbamate finishes but which will not have any drawbacks of these finishes.

Another object is to eliminate the disadvantages of excessive formaldehyde and volatility in the processing of carbamate finishes.

I Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found desirable to continue the reaction which produces the carbamates by further reacting the excess formaldehyde contained in the reaction with ethylene urea, propylene urea or glyoxal and urea.

It should be noted that the methylol derivatives of ethyl and methyl carbamate will completely volatize when exposed to temperatures of about 200 F. However, when they are further reacted With ethylene or propylene urea between 50%60% of the reaction product does not volatize. When methylol derivatives of methyl, ethyl, propyl, hydroxy ethyl, methoxy ethyl and butyl carbamate are further reacted with glyoxal and urea, the resulting product does not volatilize even when exposed to temperatures of 300 F. for 30 minutes.

The formulae are as follows:

(2) Treatment with ethylene urea to produce dimethylol ethylene urea:

(3) Treatment with propylene urea to produce dimethylol propylene urea:

(4) Treatment with glyoxal and urea to produce dihydroxy dirnethylol ethylene urea:

In the initial reaction when formaldehyde is reacted with the carbamate, it was found that the amount of formaldehyde may vary from 2 to 2.5 moles, the preferred amount being 2.25 moles. The pH must be adjusted to about 10 by the use of an alkali, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, etc.

Reaction is continued for about 1' /2 hours at 10 pH. It was found to be of importance that the pH should not drop below 9.5. The degree of methylolation is usually between and The reaction temperature is about F. to F.

The resulting product is cooled to 120 F. and pH is adjusted to 4.0 by the use of maleic acid, citric acid, tartaric acid or hydrochloric acid. Maleic acid is preferred. The product is held at a pH of 4.0 at 120 F. for about one hour.

As far as the subsequent reactions are concerned, if the excess formaldehyde is to be reacted with ethylene urea or propylene urea, pH is adjusted back to 9.5 with sodium hydroxide. Reaction is continued for 2 hours, the product is cooled and is again neutralized to 6.5 pH with a suitable acid, such as maleic acid.

Practical experimentation has shown that in the case of dimethylol methoxy ethyl carbamate the use of propylene urea lowered the free formaldehyde from a range of 6% to between 1.5 %2% of free formaldehyde.

If reaction takes place with glyoxal and urea, the pH is adjusted to from 4 to about 5 with caustic soda solution; the product is heated for 3 to 3%. hours and then cooled. No further adjustment is necessary. At this stage the free residual formaldehyde amounts to less than 1% and the product does not volatilize even at high temperatures. Experimentation with various amounts of glyoxal and urea has indicated that the amount of free formaldehyde decreases if a somewhat larger amount of urea in relation to glyoxal is used, namely for 1 mole glyoxal the urea should preferably be in the range of about 1.3 to 1.4 moles.

The following examples have been given by way of exemplification only:

EXAMPLE 1 75 gr. methyl carbamate (1 mole) are reacted with 183 gr. (2.25 moles) of 37% formaldehyde. 0.45 gr. sodium hydroxide are added to adjust the pH to 10.3. The reaction is continued for 1% hours at 158 P. Then the product is cooled to 113 F. About 1 gr. maleic acid is added to adjust the pH to 4.0. At this stage 1.71 moles of formaldehyde have been reacted, leaving 0.54 mole free formaldehyde.

Then 40.7 gr. (0.27 mole) 40% glyoxal and 16.2 gr. (0.27 mole) urea are added. The amount of urea may be increased to 0.35 mole. The reaction is continued for 2 hours at 176 F.

The resulting product is practically water white. It contains from 0.5% to 1.0% free formaldehyde and it will not volatilize at 300 F. for minutes. It is most effective as a finish for cotton fabrics and cotton polyester blend fabrics.

EXAMPLE 2 103. gr. (1 mole) propyl carbamate are reacted with 183 gr. (2.25 moles) of 37% formaldehyde. 0.45 gr. sodium hydroxide are added to adjust the pH to 10.3. The reaction is continued for 2 hours at 158 F. Then the product is cooled to 113 F. 1 gr. maleic acid is added to change the pH to 4.0. At this stage 1.75 moles of formaldehyde have been reacted, leaving 0.5 mole of formaldehyde free.

Sodium hydroxide is added to set pH at 5.0. 40.7 gr. (0.27 mole) of 40% glyoxal are added along with an amount of urea which may vary from 16.2 gr. (0.27 mole) to 21 gr. (0.35 mole). The reaction is continued for about 2 hours at about 175 F. The resulting product contains 0.5% to 1.0% free formaldehyde, it will not volatilize readily and it produces an excellent finish.

EXAMPLE 3 89 gr. (1 mole) ethyl carbamate are reacted with 183 gr. (2.25 moles) of 37% formaldehyde. 0.45 gr. sodium hydroxide are added. The reaction is continued for 1% hours at 158 F. Then the product is cooled to 113 F. and citric acid is added to set the pH at 4.0. At this stage 1.8 moles of formaldehyde have been reacted, leaving 0.45 mole of free formaldehyde.

Sodium hydroxide is added to set pH at 5.5. 40.7 gr. (0.27 mole) of 40% glyoxal are added with 16.2 gr. (0.27 mole) urea. The reaction is continued for 2 hours 4 at 175 F. The resulting product contains 0.5% to 1.0% free formaldehyde; it will not volatilize readily and it produces an excellent finish.

EXAMPLE 4 119 gr. (1 mole) methoxy ethyl carbamate are reacted with 183 gr. (2.25 moles) of 37% formaldehyde. 1 gr. potassium hydroxide is added to adjust the pH to 10.2. The reaction is continued for 1% hours at F. Then the product is cooled to 113 F. Citric acid is added to set the pH at 4.0. At this stage 1.7 moles of formaldehyde have been reacted, leaving 0.55 mole of free formaldehyde.

Sodium hydroxide is added to set pH at 5.5. 47 gr. (0.27 mole) of 40% glyoxal are added along with 21.6 gr. (0.36 mole) urea. The reaction is continued for about 2 hours at about F. The resulting product contains 0.5% to 1.0% free formaldehyde; it will not volatilize readily and it produces an excellent finish.

EXAMPLE 5 105 gr. (1 mole) hydroxy ethyl carbamate are reacted with 203 gr. (2.5 moles) of 37% formaldehyde. 1.8 gr. sodium hydroxide are added to adjust the pH to 10.5. The reaction is continued for 1% hours at 158 F. Then the product is cooled to 113 F. Citric acid is added to adjust the pH to 4.0. At this stage approximately 1.8 moles of formaldehyde have been reacted, leaving 0.7 mole of free formaldehyde.

Sodium hydroxide is added to set pH at 5.0. 52.2 gr. (0.35 mole) of 40% glyoxal and 21 gr. (0.35 mole) urea are added. The reaction is continued for 2 hours at 176 F. The resulting product contains 0.5% to 1% free formaldehyde; it will not volatilize readily and it produces an excellent finish.

TREATMENT OF FABRIC All of the above described products are used in essentially the same manner, namely, a bath is prepared containing 10% to 35%, preferably 15% to 25% of the prod net in water and from 1% to 2% of a catalyst which is a metallic salt of a strong acid, such as magnesium chloride, zinc chloride or zinc nitrate. The fabric is conventionally treated in the bath by pad application. Then the fabric is dried at 200 F .-240 F. for 4 to 8 minutes and is cured at 300 F. to 350 F. for 1 to 3 minutes. As already stated, cotton and cotton polyester blend fabrics are particularly suitable for these treatments.

Fabrics which are those finished have excellent crush resistance and dimensional control as well as all other advantageous properties which are at least as good as those imparted to fabrics by prior art carbamate finishes. Furthermore, they have the additional advantages as compared to prior art carbamate finishes, that the amount of free formaldehyde is reduced to a negligible quantity and that the finish is non-volatile. Accordingly, the carbamate finishes of this invention can be used satisfactorily in permanent press processing.

It is apparent that the examples described above have been given solely by way of illustration and not by way of limitation and that they are capable of many variations and modifications within the scope of the present invention. All such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. A finish for textile fabrics comprising a material resulting from a first reaction of one molar part of a carbamate compound selected from the group consisting of methyl carbamate, ethyl carbamate, propyl carbamate, methoxy-ethyl carbamate, hydroxy-ethyl carbamate and butyl carbamate with more than two molar parts of formaldehyde under reaction conditions of elevated temperature and alkaline pH and carrying forward said reaction as far as it will go and thence reacting all of the excess formaldehyde from said first reaction and in the presence of said product of said first reaction in a second reaction with a sufiicient amount of a compound selected from the group consisting of ethylene urea, propylene urea and combined glyoxal and urea at elevated temperatures and at a pH of from 5 to 9 and carrying forward said second reaction as far as it will go.

2. A finish for textile fabrics as described in claim 1 the reactant used to react with said excess formaldehyde from said first reaction being combined glyoxal and urea in proportion of one molar part of glyoxal to at least 1.3 molar parts of urea.

3. A textile fabric having the finish of claim 1.

References Cited UNITED STATES PATENTS 2,937,966 5/1960 Updegraif et al. 26029.4 3,052,570 9/1962 Polansky et al 260849 3,211,805 10/1965 Herbes et a1. 260849 3,219,632 11/1965 Frick et a1. 260-29.4

JOAN C. BLEUTGE, Primary Examiner US. Cl. X.R. 

